subs. (common).Generic for the female sex. Thus, BROTHER (or KNIGHT, or SQUIRE) OF THE GUSSET = a pimp; GUSSETTING = wenching; GUSSETEER = a wencher; etc.
GUSSET OF THE ARSE, subs. phr. (common).The inside edge of the buttocks.
d. 1796. BURNS, The Merry Muses, pp. 99100. An he grippit her fast by the GUSSET OF HER ARSE.